Abstract: Offshore oil and gas development is conducted far away from the land, and the communication and network deployment face great challenges. Intelligent perception technology is one of the difficult problems that must be solved in the development of offshore intelligent drilling and completion. Offshore intelligent drilling and completion technology is the organic integration of offshore drilling and completion engineering and advanced technologies such as artificial intelligence, big data, and cloud computing, which can realize fine characterization, decision optimization, and closed-loop control of offshore oil and gas drilling and completion process and greatly improve drilling and completion efficiency and oil and gas recovery efficiency. To this end, the current technical difficulties of offshore intelligent drilling and completion in infrastructure construction, intelligent drilling, and intelligent wellbore were analyzed. The key technologies in the field of intelligent perception in offshore drilling and completion were studied from four aspects of formation, tools, fluids, and equipment, and an intelligent monitoring system for offshore drilling was constructed to realize a comprehensive perception of the whole life cycle of offshore drilling and completion. After the application of the intelligent monitoring system for offshore drilling, the platform had no safety accident from drilling to completion of the first batch of development wells. The key intelligent perception technologies for offshore drilling and completion, as the basis for the construction of offshore intelligent drilling and completion, provide technical support for promoting the digital transformation and intelligent development of offshore oil and gas fields.